1. Field of the Invention
The present invention is directed at methods for treating cognitive/attention deficit disorders in general using tetrahydroindolone derivatives and analogues, particularly tetrahydroindolone derivatives or analogues in which the tetrahydroindolone derivative or analogue is covalently linked to another moiety to form a bifunctional conjugate. More specifically, the present invention is directed at methods and compositions for treating attention deficit disorder and attention deficit hyperactivity disorders in adults and children as well as mild cognitive impairment and dementia.
2. General Background and State of the Art
Cognitive/attention deficit disorders adversely affect life quality and productivity for millions of persons worldwide. Cognitive/attention deficit disorders such as attention deficit disorder (ADD), attention deficit-hyperactivity disorder (ADHD), mild cognitive impairment and dementia affect both children and adults. In many cases the organic cause remains unknown and presumed inherited. In others, cognitive/attention deficit disorders can be inducing by trauma, disease or aging. Moreover, in many persons mild cognitive impairment may not rise to a clinically identifiable level consequently, these individuals are never labeled ADD or ADHD. However, mild cognitive impairment often results in an inability to concentrate and perform basic tasks associated with normal productive lives.
Cognitive/attention deficit disorders are not only devastating to the afflicted individuals and their family, but society as a whole suffers. Our cultures and economies are deprived the productive contributions that afflicted persons would ordinarily make. Moreover, in many cases society must bear the costs of hospitalizing, incarcerating and/or institutionalizing victims of cognitive/attention deficit disorders.
These disorders are also extremely difficult to treat effectively because of the multiplicity of the symptoms and etiologies. Although many alternative and combination drug therapies have been attempted and proposed, an effective treatment remains elusive. The most common medications used to treat ADD and/or ADHD are stimulants medications, anti-depressant medications, and even anti-convulsant medications. Stimulant medications include Ritalin® (methylphenidate), Dexedrine® (dextroamphetamine), Adderall®, and Cylert® (sodium pemoline). However, these medications, while effective in many persons, are not without side effects.
Ritalin® is the most commonly used stimulant; however, adverse side effects are frequent and include nervousness, insomnia anorexia, and cardiovascular changes. Furthermore, Ritalin® is counter indicated in patients exhibiting anxiety, tension, and agitation. All symptoms commonly associated with ADD and ADHD.
Recently, the diet control medication Obetrol® has been used for treating ADD and ADHD. Obetrol® has been renamed Adderall® and is Dexedrine®/amphetamine composite medication. Adderall® is considered to be less harsh than Ritalin® but is still associated with many adverse side effects including nervousness, insomnia, loss of appetite, addiction, high blood pressure, rapid pulse rate, feelings of suspicion and paranoia. Cylert® is another commonly used central nervous system stimulant. Cylert® (permoline) is an oxazolidine compound known to cause hepatic impairment in many patients. In fact, Canada has recently decertified Cylert® because of the high rate of liver damage associated with its use. Moreover, Cylert® has proven to be ineffective in many patients.
Unfortunately, the many severe side effects associated with conventional ADD and ADHD therapies has caused patent to seek unproven alternative therapies. These include biofeedback, restricted diets, allergy treatments, medicines to correct problems in the inner ear, megavitamins, chiropractic adjustment and bone re-alignment, treatment for yeast infection, eye training and special colored glasses. While most of these alternative therapies do no harm, they can be costly and generally do not provide sustained relief from ADD and ADHD symptoms. Therefore, there remains a need for clinically proven pharmaceutical compositions that palliate the symptoms associated with ADD and ADHD without side effects commonly associated with conventional simulate-based therapies.